Centrifugal fan

ABSTRACT

A centrifugal fan includes a fan frame, an impeller and a motor. The fan frame includes a base plate, a sidewall and a plurality of air deflectors. The sidewall and the air deflectors are disposed on the base plate. The base plate, the sidewall and the air deflectors form an accommodating space and an air outlet. The impeller is disposed in the accommodating space. There is a flow channel between the impeller and the sidewall. The motor is connected with the impeller and drives the impeller to rotate. The air deflectors are set separately along the extension direction of the flow channel and toward to the air outlet. The distance between the air deflector which is closer to the air outlet and the impeller is larger.

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-provisional application claims priority to 201410689760.8 filed in People's Republic of China on Nov. 25, 2014, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention is relative to a centrifugal fan, especially relative to a centrifugal fan for increasing the input air and with stable output air.

2. Related Art

In recent years, with advances in technology, the electronic devices (ex: notebook) are gradually developing with high-performance, high speed and high frequency. Accordingly the computing loading of the inside components of the electronic device increases and the temperature of the electronic device is getting higher. If a good heat dissipation solution is not utilized efficiently in the electronic device, the stability will be influenced and the life of the electronic device will be shortened. Thus, generally a fan (ex: centrifugal fan) will be installed inside of the electronic device for heat dissipation.

FIG. 1 is a top view of a prior art centrifugal fan 1. As shown in FIG. 1, the centrifugal fan 1 includes an air outlet O1 and an air inlet (not shown). A sidewall 11 is disposed besides a flow channel P1 of the centrifugal fan 1. The input air is limited to the size and the position of the air inlet. The input air is difficult to increase. Additionally, the centrifugal fan 1 has a non-uniform problem that the output air is collected at the strong wind area H.

For overcoming the above problems, industries provide a centrifugal fan with different structure as shown in FIG. 2. FIG. 2 is a top view of an additional prior art centrifugal fan 2. The centrifugal fan 2 includes a base plate 21, a sidewall 22 and an air inputting structure 23. The air inputting structure 23 includes an air inlet 231 and air deflectors 232. The air inlet 231 is disposed on the sidewall 22. The air deflectors 232 are disposed adjacent to the air inlet 231. The air deflectors are extended towards the flow channel P2. Although the purpose of the air inlet 231 is for increasing the input air, the air deflectors 232 occupied some space of the original flow channel P2 and the space of flow channel P2 is limited accordingly. In the real implement, the structure in FIG. 2 can not increase the input air. Additionally, the above structure in FIG. 2 makes the inner air pressure of the centrifugal fan 2 unstable, the fan characters getting worse, and noisy. Moreover, the dust inside of the centrifugal fan or the dust outside of the centrifugal fan that is inputted into the air inputting structure 23 are easily to accumulated at the guiding part 2321 of the air deflectors 232. Thus drags around the air inlet 231 increase, and the outside air difficultly flows into the centrifugal fan 2 via the air inlet 231.

In view of above problems, recently the most electronic devices are developed to have a thinner size. The thinner size of the electronic devices will decrease the inner space of the electronic devices. Accordingly, it is an important subject to provide a centrifugal fan with an increasing input air and a stable/uniform output air in the same fan volume.

SUMMARY OF THE INVENTION

In view of foregoing subject, an objective of the present invention is to provide a centrifugal fan with an increasing input air and a stable/uniform output air in the unchanged volume of the fan.

For achieving the above objective, the present invention discloses a centrifugal fan including a fan frame, an impeller, and a motor. The fan frame includes a base plate, a sidewall and a plurality of air deflectors. The sidewall and the air deflectors are disposed on the base plate. An accommodating space and an air outlet disposed by the base plate, the sidewall and the air deflector. The impeller is received in the accommodating space. A flow channel is disposed between the impeller and the sidewall of the fan frame. A motor is connected with the impeller and drives the impeller to rotate. The air deflectors are set separately along the extension direction of the flow channel and toward to the air outlet. A distance is disposed between the air deflector and the impeller. The distance increases when the air deflector is closer to the air outlet.

In one embodiment, the two adjacent air deflectors are partially overlapped along a predetermined direction.

In one embodiment, the impeller includes a rotation center, an air deflector includes an end adjacent to an additional air deflector, and the predetermined direction is a direction from the rotation center to the end of the air deflector.

In one embodiment, the air deflectors at least include a first air deflector and a second air deflector. A distance between the second air deflector and the air outlet is smaller than a distance between the first air deflector and the air outlet. The second air deflector and the impeller are separately disposed two opposite sides of the air deflector.

In one embodiment, a gap is disposed between the two adjacent air deflectors, an outside airflow flows into the centrifugal fan via the gap, and the flow direction of the outside airflow is along an extension direction of the flow channel.

In one embodiment, the sidewall comprising a throat part, the air deflectors and the throat part are disposed at two opposite sides of the impeller.

In one embodiment, the air deflectors are arc-shaped.

In one embodiment, dusts in the centrifugal fan are exhausted from the centrifugal fan via a space between the two adjacent air deflectors when the impeller is driven to rotate reversely by the motor.

According to above, the centrifugal fan of the present invention can increase the input air by that air deflectors set separately and along the extension direction along the flow channel and towards to the air outlet and the outside airflow can flow in the fan via the space between the two adjacent air deflectors. Additionally, the airflow flowing into the fan can be flowing along the air deflectors to the air outlet for stable/uniform output air.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a top view of a centrifugal fan of the prior art;

FIG. 2 is top view of an additional centrifugal fan of the prior art;

FIG. 3A is an exploded view of a centrifugal fan according to a preferred embodiment of the present invention;

FIG. 3B is a top view of the centrifugal fan in FIG. 3A;

FIG. 3C is a schematic diagram when the centrifugal fan reversely rotates; and

FIG. 4 is a schematic diagram of different types of air deflector of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

FIG. 3A is an exploded view of a centrifugal fan according to a preferred embodiment of the present invention and FIG. 3B is a top view of the centrifugal fan in FIG. 3A. For easily understanding, FIG. 3B does not show the top plate 314 in FIG. 3A. Referring to FIGS. 3A and 3B, the centrifugal fan 3 of this embodiment includes a fan frame 31, an impeller 32 and a motor 33. The centrifugal fan 3 can be received in an electronic device as a heat dissipation system. The electronic device can be a notebook computer.

The fan frame includes a base plate 311, a sidewall 312 and a plurality of air deflectors 313. In the embodiment, the centrifugal fan includes three air deflectors. However, the number of the air deflector can depend on real requirements.

The sidewall 312 and the air deflectors 313 are disposed on the base plate 311. An accommodating space S and an air outlet O2 is disposed by the base plate 311, the sidewall 312 and the air deflectors 313.

The impeller 32 includes a wheel 321 and a plurality of fan blades 322. The impeller is received in the accommodating space S and mounted on the motor 33. The motor is connected with the impeller 32 and drives the impeller 32 to rotate. A flow channel P3 (as shown in FIG. 3B) is disposed between the impeller 32 and the sidewall 312. In the embodiment, the fan frame 31 further includes a top plate 314. An air inlet O3 is disposed in the top plate 314. When the impeller is rotating, the outside air flows into the centrifugal fan 3 via the air inlet O3 and the air in the centrifugal fan 3 flows along the flow channel P3 to the air outlet O2. Then the air in the centrifugal fan 3 is exhausted via the air outlet O2.

In the embodiment, the air deflectors 313 are separately disposed along the extension direction of the flow channel and toward to the air outlet O2. In detail, the sidewall 312 in the embodiment includes a throat part 3121 and a guiding part 3122. The throat part 3121 and the guiding part 3122 are respectively disposed at two ends of the sidewall 312. The air deflectors 313 are separately disposed from the position adjacent to the guiding part 3122 and toward to the air outlet O2. The air deflectors 313 and the throat part 3121 are disposed on the two sides of the impeller 32. According to that the air deflectors are separately disposed, a gap D is formed between the two adjacent air deflectors 313. In the embodiment, a distance of the gap D optimally is between 0.5 mm to 10 mm. In the embodiment, when the impeller is rotating, outside airflow can flow into the centrifugal fan 3 via the gap D, the air in the centrifugal fan 3 flows along the extension direction of the flow channel P3 for increasing the input air.

In the embodiment, the outside air that flows into the centrifugal fan 3 can be guided to a low air pressure position by the air deflectors 313. In FIG. 3B, the air deflectors 313 are arc-shaped. The outside airflow can be guided to a position near to the middle of the air outlet O2 for the stable/uniform output air around the air outlet O2. It is noted that the shape of the air deflectors can be adjusted according to the real requirements, and it is not limited to shapes of the air deflectors as shown in FIGS. 1-5.

The following descriptions are relative to the relative positions of the air deflectors 313.

In the embodiment, the air deflectors 313 at least include a first air deflector 3131 and a second air deflector 3132. A distance between the second air deflector 3132 and the air outlet O2 is smaller than a distance between the first air deflector 3131 and the air outlet O2. The second air deflector 3132 and the impeller 32 are disposed two opposite sides of the first air deflector 3131.

In detail, the first air deflector 3131 includes a first end 3131 a and a second end 3131 b. The second end 3131 b is disposed adjacent to the second deflector 3132. The second air deflector 3132 includes a third end 3132 a and a fourth end 3132 b. The third end 3132 is adjacent to the first air deflector 3131. The third end 3132 a and the impeller 32 are disposed two opposite sides of the second end 3131 b. It means that the second air deflector 3132 is located at outside of the first air deflector 3131.

In centrifugal fan 3 according to the embodiment of the present, the position of the air deflector 313 that is closer to the air outlet O2 is disposed farther than the position of the air deflector 313 that is father from the air outlet O2. Therefore, the air deflectors 313 will not decrease the space of the whole flow channel and prevent to decrease the air inside the centrifugal fan.

Additionally, in the embodiment, the two adjacent air deflectors 313 are partially overlapped along a predetermined direction. In FIG. 3B, the first air deflector 3131 and the second air deflector 3132 are partially overlapped in the predetermined direction d3. In detail, the second end 3131 b of the first air deflector 3131 and the third end of the second air deflector 3132 are overlapped in the predetermined direction d3. The impeller 32 includes a rotation center C. The predetermined direction d3 is a direction from the rotation center C to the second end 3131b. Thus, when the impeller 32 rotates forwardly, the air in the centrifugal fan 3 exhausted via the gap D between the air deflector 3131 and the second air deflector 3132 can be prevented.

In the embodiment, the gap D is also disposed between the first end 3131 a of the first air deflector 3131 and the guiding part 3122. The gap D is utilized for increasing the input air. The distance between the first air deflector 3131 and the impeller 32 is larger than the distance between the sidewall 312 and the impeller 32. Accordingly the space of the flow channel will not be decreased by the first air deflector 3131.

The distance between the sidewall 312 and the impeller 32, the distance between the first air deflector 3131 and the impeller 32, and the distance between second air deflector 3132 and the impeller 32 are increasing in turn. A width of the flow channel is larger increasingly. There is enough space that the outside airflow can flow via the gap D for increasing the air in the centrifugal fan 3.

Additionally, in the embodiment, when the motor drives the impeller 32 to rotate reversely, a reverse airflow is generated in the centrifugal fan 3. Dusts in the centrifugal fan 3 can be exhausted from the centrifugal fan 3 via the gap D between the two adjacent air deflectors to achieve the dust-removing function. A shape of the air deflectors 313 is arc-shaped to match the flow direction of the flow field. The dusts in the centrifugal fan 3 can be flowed along the arc-shaped air deflector and exhausted via the gap D

Referring to FIG. 4, FIG. 4 is a schematic diagram of different types of air deflector of the present invention. Different from the air deflectors 313 in FIG. 3, a shape of air deflectors 313 a in FIG. 4 is similar to a rectangle in a top view. Other characters of the centrifugal fan 3 in FIG. 4 are similar to that of the centrifugal fan 3 in FIG. 3. Please referring the preceding paragraphs and they are not repeated again.

In summary, in the centrifugal fan, the air deflectors are disposed separately along the extension direction and toward to the air outlet. The outside airflow can flow in the centrifugal fan via the gap between the two adjacent air deflectors. Thus, the input air is increased. Additionally, the inside airflow can flow along the air deflectors to the air outlet for unifying the output air.

Comparing to the prior art, the flow channel of the centrifugal fan is not reduced according to the air deflectors. The centrifugal fan can overcome the problem that the air pressure in the fan is not uniform and noisy. Additionally, the dust in the fan can be exhausted easily, and is not accumulated in the gap.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention. 

What is claimed is:
 1. A centrifugal fan comprising: a fan frame comprising a base plate, a sidewall and a plurality of air deflectors, the sidewall and the air deflectors are disposed on the base plate, an accommodating space and an air outlet disposed by the base plate, the sidewall and the air deflector; an impeller received in the accommodating space, a flow channel disposed between the impeller and the sidewall of the fan frame; and a motor connected with the impeller and driving the impeller to rotate; wherein the deflectors are set separately along the extension direction of the flow channel and toward to the air outlet, a distance is disposed between the air deflector and the impeller, and the distance increases when the air deflector is closer to the air outlet.
 2. The centrifugal fan of claim 1, wherein the two adjacent air deflectors are partially overlapped along a predetermined direction.
 3. The centrifugal fan of claim 2, wherein the impeller comprises a rotation center, an air deflector comprises an end adjacent to an additional air deflector, and the predetermined direction is a direction from the rotation center to the end of the air deflector.
 4. The centrifugal fan of claim 1, wherein the air deflectors at least comprises a first air deflector and a second air deflector, a distance between the second air deflector and the air outlet is smaller than a distance between the first air deflector and the air outlet, and the second air deflector and the impeller are separately disposed two opposite sides of the air deflector.
 5. The centrifugal fan of claim 1, wherein a gap is disposed between the adjacent two air deflectors, an outside airflow flows into the centrifugal fan via the gap, and the flow direction of the outside airflow is along an extension direction of the flow channel.
 6. The centrifugal fan of claim 1, wherein the sidewall comprises a throat part, and the air deflectors and the throat part are disposed at two opposite sides of the impeller, respectively.
 7. The centrifugal fan of claim 1, wherein the air deflectors are arc-shaped.
 8. The centrifugal fan of claim 1, wherein dusts in the centrifugal fan are exhausted from the centrifugal fan via a space between the two adjacent air deflectors when the impeller is driven to rotate reversely by the motor. 